Turbine engine with struts

Abstract

An apparatus and method relating to a turbine engine with an annular frame about a centerline defining an axial direction, the annular frame formed from an inner frame wall and an outer frame wall disposed around and radially spaced from the inner frame wall to define an annular airflow passage between the inner and outer frame walls. The annular frame further includes at least two struts each extending between a root at the inner frame wall and a tip at the outer frame wall to define a span-wise direction.

What is claimed is: 
     
         1 . A turbine engine with an annular frame about a centerline defining an axial direction, the annular frame comprising:
 an inner frame wall;   an outer frame wall disposed around and radially spaced from the inner frame wall to define an annular airflow passage between the inner frame wall and the outer frame wall; and   a set of struts circumferentially disposed about the annular airflow passage comprising at least two struts each extending between a root at the inner frame wall and a tip at the outer frame wall to define a spanwise direction and having different airfoil shapes, the airfoil shapes differing from each other in at least one of an amount of twist along the spanwise direction, an amount of chord length along the axial direction, or an amount of camber,   wherein the at least two struts are variably spaced circumferentially about the annular airflow passage, or the at least two struts are staggered in the axial direction, or both.   
     
     
         2 . The turbine engine of  claim 1 , wherein an airfoil shape defines an airfoil cross-sectional area extending from a leading edge to a trailing edge in the axial direction and defining an airfoil height. 
     
     
         3 . The turbine engine of  claim 2 , wherein the at least two struts have different airfoil heights. 
     
     
         4 . The turbine engine of  claim 2 , wherein the amount of twist is a degree of rotation of the airfoil cross-sectional area about a radial axis extending through a strut of the set of struts in the spanwise direction. 
     
     
         5 . The turbine engine of  claim 1 , wherein at least one of the at least two struts has a symmetrical airfoil cross-sectional area. 
     
     
         6 . The turbine engine of  claim 1 , wherein the at least two struts are three or more struts. 
     
     
         7 . The turbine engine of  claim 6 , wherein the three or more struts vary in chord length or camber, or both with respect to each other. 
     
     
         8 . The turbine engine of  claim 1 , wherein the annular frame is a compressor frame. 
     
     
         9 . A turbine engine with an annular frame about a centerline defining an axial direction comprising:
 an inner frame wall;   an outer frame wall disposed around and radially spaced from the inner frame wall to define an annular airflow passage in the axial direction between the inner frame wall and the outer frame wall; and   at least two struts each extending between a root at the inner frame wall and a tip at the outer frame wall to define a spanwise direction and having airfoil shapes, the at least two struts arranged in at least one of an axially staggered pattern or a circumferentially variably spaced pattern.   
     
     
         10 . The turbine engine of  claim 9 , wherein the at least two struts have different airfoil shapes, the airfoil shapes differing from each other in at least one of an amount of a twist along the spanwise direction, an amount of a chord length along the axial direction, and an amount of a camber. 
     
     
         11 . The turbine engine of  claim 10 , wherein an airfoil shape defines an airfoil cross-sectional area extending from a leading edge to a trailing edge in the axial direction and defining an airfoil height. 
     
     
         12 . The turbine engine of  claim 11 , wherein the twist is a degree of rotation of the airfoil cross-sectional area about a radial axis extending through a strut in the at least two struts in the spanwise direction. 
     
     
         13 . The turbine engine of  claim 9 , wherein the at least two struts have different airfoil heights. 
     
     
         14 . The turbine engine of  claim 13 , wherein the at least two struts are three or more struts. 
     
     
         15 . The turbine engine of  claim 14 , wherein the three or more struts vary in chord length or camber with respect to each other. 
     
     
         16 . The turbine engine of  claim 9 , wherein at least one of the at least two struts has a symmetrical airfoil cross-sectional area. 
     
     
         17 . The turbine engine of  claim 9 , wherein the annular frame is a compressor frame. 
     
     
         18 . A method of controlling a pressure field entering a compressor section of a turbine engine, the method comprising:
 passing air through an annular frame extending from an inlet to an outlet and defining an annular airflow passage;   flowing the air along at least two struts located within the annular airflow passage and having an airfoil shape, the at least two struts being variably spaced circumferentially about the annular airflow passage, or the at least two struts being staggered in an axial direction, or both; and   controlling a wake of air proximate the outlet by at least one of the following:
 varying a chord length of at least one strut with respect to a second strut, or 
 varying a camber of the at least one strut with respect to the second strut. 
   
     
     
         19 . The method of  claim 18 , wherein the controlling further includes twisting the at least two struts with respect to a radial axis extending in a spanwise direction from a root along an inner frame wall to a tip along an outer frame wall of the annular frame. 
     
     
         20 . The method of  claim 18 , wherein the controlling further includes varying an airfoil height of a first strut of the at least two struts with respect to the second strut of the at least two struts.